U.S. Pat. No. 4,616,798, as owned by the assignee of this application, illustrates a support mechanism which interconnects an auxiliary work support to a main work support. The support mechanism enables the auxiliary work support and a keyboard thereon to be moved in-and-out, sidewardly, and up-and-down relative to the main work support. In addition, the auxiliary work support can be disposed in a lowermost position and then moved inwardly into a storage position beneath the main work support. The mechanism of the aforementioned patent has proven highly desirable and has met with significant commercial success in view of the extreme versatility and convenience which it provides. However, the improved support mechanism of this invention has been developed so as to provide even greater convenience of use and operator flexibility.
In the improved support mechanism of the present invention, a vertically swingable linkage is preferably connected at its inner end to a vertical pivot structure, the latter being carried by a carriage slidably supported on the underside of the main work support. A cam mechanism cooperates between the carriage and the vertically swingable linkage, which cam mechanism provides a three-dimensional cooperation so as to automatically swing the linkage and the auxiliary work support downwardly to a predetermined elevation when the auxiliary work support is moved either inwardly or sidewardly relative to the main work support beyond a predetermined position. The auxiliary work support and the keyboard thereon are hence automatically cammed downwardly to prevent the keyboard from being hit by the main work support and knocked off of the auxiliary work support.
In the improved arrangement of this invention, the cam and vertical pivot also provide increased capability in terms of accomplishing the above while permitting the overall height of the structure to be minimized, particularly in the vicinity of the carriage as mounted adjacent the underside of the main work support, and at the same time greatly facilitate the swinging of the linkage through a full 360.degree. so that such swinging can be accomplished without encountering stops.
Other objects and purposes of the invention will be apparent to persons familiar with structures of this general type upon reading the following specification and inspecting the accompanying drawing.